Effect Of Fungicides On Decontamination And Survival Of In Vitro Cultured Coffea Arabica L. Explants

Abstract

Coffee stands out as one of Brazil's main agricultural commodities, with Coffea arabica L. being the most economically important. In vitro micropropagation is an essential tool for producing uniform and healthy seedlings; however, microbial contamination remains the main obstacle to crop establishment. This study aimed to evaluate the effect of different fungicides and concentrations on surface disinfection and survival of C. arabica explants cultivated in vitro. Leaf and meristematic explants were subjected to a surface asepsis protocol and inoculated in Woody Plant Medium (WPM) culture medium, under eight treatments containing the fungicides tebuconazole and azoxystrobin, alone or in combination, with four replicates each. The variations tested included fungal and bacterial contamination and survival for 28 days. The data were subjected to Generalized Linear Models (GLM) with binomial distribution and paired comparisons using Fisher's exact test with Holm correction. The results indicated a significant effect (p < 0.05) of the treatments for all variables. Although paired comparisons did not show isolated differences after multiple test correction, biological superiority was observed in the treatment with azoxystrobin (1 mL·L⁻¹), which showed a total absence of contaminants and 100% survival. These findings suggest that strobilurins favor the balance between sanitary control and the physiological integrity of the explant. It is concluded that the strategic use of fungicides in the culture medium is promising for improving the in vitro establishment of coffee plants, and a larger sample size is recommended to validate the ideal dosages and mitigate the effects of oxidative phytotoxicity.